Art of making metallo-organic compounds



Patented Aug. 23, 1927.

UNITED STATES PATENT OFFICE.

CHARLES A. KRA'US AND CONRAL O. OAIILIS, OF WORCESTER, MASSACHUSETTS, AS- SIGNORS TO STANDARD DEVELOPMENT COMPANY," A CORPORATION 01' DELA- wens.

Io Drawing. Application fled April 13,

This invention relates to the art of mak ing metallo-orga'nic compounds, and will be fully understood from the following'description: In the preparation of hydrocarbon compounds of metals heretofore the methods followed have been based upon the action of iodids, or unstable compounds of zinc. etc. Thesemethods have been characterized by high cost and uncertain yields. and at-' tended with variousoperating difliculties. Inthe experiments recorded in the literature, where alloys containing sodium have been used pressure has been avoided, the alloybeing heated with an alkyliodidunder a reflux condenser (Lowig. Annalen (1. Chem. '84. 308; Lowig, J our. Prak. Chem. 60,

304: Klippel. Jour. Prak; Chem. 81, 287

Ladenburg, 7 5. 78).

In proceeding in accordance with the presentinvention, the metal to be used, is, in advantageous condition for reaction, (as for instance in alloy with a highly electiopositive metal, as an alkali metal -or alkaline earth metal), subiected to a reagent involving a direct transfer of-hydrocarbon radicals, as-more particularly pointed out hereinafter. In the case of a metal of the second sub-group of the. fourth periodic group, (tin, lead, germanium), sodium for instance is. preferably employed as the alloy ingredient. For brevity, the metals mentioned will be referred to herein as metals of the tin sub-group.

.. As an example,

nn. d. Chem. Supplement 8,

tin in the proportion of 80-94% is suitably alloyed wlth sodium 111 the complemental proportions of 4%, (preferably 86% of tin and 14% of sodium, corresponding to the formula Na Sn,) and the alloy is subdivided to suitable size, as for instance about the size of wheat grains, and introduced into a reaction vessel capable of withstanding pressure, and equipped with suitable heating and cooling means, as a jacket or coils, also stirring means, so as to afiord a .close temperature control, as it is desired that-local rises or irregularities in ART OF MAKING METALLO-ORGANIC 192:. Serial no. 031340.

temperature should not occur. The vessel may be mounted for rotation and contain 59 balllls or the like inthe manner of a ball m1 Methyl chlorid being introduced into the reaction vessel in suitable amount (before or after the introduction of the alloy. as de- 55' sired), and the alloy being suitably subdivided, the reaction is. ready to proceed. Ordinarily, to start the reaction, slight warming, say up to about C. is desirable, but after the reaction is well under way, 00 more or less cooling is ofdinarily required. By the use of a closed, pressure-resistant vessel, the methyl chlorid, although lowboiling, can be held under pressure, and. at'

the said temperature or slightly-above, to 65 about (1,- and finally when well toward .the end, even as high as 100 C. 'On completionof the reaction, which requires about 2-24 hours, depending upon the conditions,

ppfactically pure tin tetramethyl can be taken 70 Instead of methyl chlorid, other desired alkyl chlorids or bromids can be employed; for instance ethyl 'chlorid or ethyl bromid may be used and the corresponding tin l5 tetraethyl obtained. I

If desired, a catalyst may be employed, as for example zinc. In using the zinc, this, to .the amount of about 0.5 to 3% may convenient lybe initially alloyed with the tin and sodium. The use of a catalyst promotes the reaction of the alkyl halid, and particularly where the sodium or the like is not in molecular proportion with the tin or lead.

' In general, in order to facilitate the reaction, it is desirable to employ more than the calculated molecular equivalent of ,the methyl -ch1orid or other hydrocarbon ha'lid used. In such case, after completion of the reaction, the excess may be recovered, as by distilling ofi, or it. may be advantageous to use an exhaust pump. The methyl chlorld so recovered. is condensed or re-compressed and condensed and may be employed 1n suba sequent reactions. The surplus methyl chlorid. having een removed, e reactlon densation, and a final filtration and drying may be carried out if desired. In the case of the lower boiling organic tin compounds, the desired product may, if preferred, be removed from the reaction vessel by ordinary distillation.

The residue in the reaction vessel contains tin and sodium chlorid. By repeated leaching and washing with water, the Sodium chlorid may be removed, and the tin in divided condition may be dried and after alloying be used'for subsequent reactions.

Instead of tin as in the illustration detailed, other metals, as for example .lead, may be employed, and the corresponding metallo-organic compound obtained; "While the invention is directed especially to the production of compounds in which all the valences of the metal are satisfied by hydrocarbon groups, such as tin tetramethyl, lead tetraethyl etc., it is also applicable for the preparation of compounds in which only a portion of the valences of the metallic atom are satisfied with hydrocarbon radicals.

While the invention has been described by reference to certain specific details," it will be understood that this is for the purpose of illustration and is not limitative; and changes may be made which come within the spirit and scope of the invention' What we claim is:

1. The improvement in the art of making tin tetramethyl, which comprises alloying tin With sodium in the proportions of about 86% of tin and 14% of sodium, subdividing the alloy, and reacting upon the alloy with methyl chlorid under pressure at a temperature between about 30 and 100 C. in the presence of zinc as a catalyst.

2. The improvementin the art of making tin tetramethyl, which comprises alloying tin with sodium, subdividing the alloyand reacting upon the alloy with methyl chlorid while maintaining the temperature above the normal boiling point of methyl chlorid.

3. The improvement in the art of making hydrocarbon compounds of metals of the tin sub-group, which comprises alloying the metal with sodium, sub-dividing the alloy and reacting upon the alloy with an alkyl chlorid in the presence of a catalyst, while maintaining the temperature above the normal boiling point of the alkyl chlorid.

' 4. The im rovement inthe art of making metallo-alky' compounds of metals of the tin suboup, which comprises alloying the metal with sodium, and reacting upon the metallo-alkyl compounds of metals of the tin sub-group, which comprises alloying the metal with sodium, and reacting upon the alloy with an alkyl chlorid while maintaining a temperature above the normal boiling point of the alkyl chlorid.

6. The improvement in the art of making metallo-alkyl compounds of metals of the tin sub-group, which comprises alloying the metal with sodium, and reacting upon the alloy with an alkyl halid in which the halogen has a lower atomic weight than iodin'. in the presence of a catalyst while maintaining a temperature above the normal boiling point of the alkyl halid.

7. The improvement in the art of making metallo-alkyl compounds of metals of the tin sub-group, which comprises subjecting the metal in alloy with sodium to the action of an alkyl halid whose halogen is of a lower atomic weight than iodin, in the presence of a catalyst while maintaining a temperature fibp e the normal boiling point of the alkyl 8. The improvement in the art of making metallo-alkyl compounds of metals of the tin sub-group, which comprises subjecting the metal in alloy with a highly electropositive metal to the action of an alkyl halid in which the halogen has a lower atomic weight than iodin, in the presence of a catalyst while maintaining a pressure above normal atmospheric pressure.

9. The improvement in the art of making metalloealkyl compounds of metals of the tin sub-group, which comprises subjecting the metal in alloy with ahighly electropositive metal to the action of an alkyl halid 1n which the halogen has a lower atomic weight than iodin, in the presence of a catalyst while maintaining a tem erature above the normal boiling point of t e alkyl halid.

'10. The improvement in the art of making metallo-alkyl compounds of metals of the the metal in alloy with an alkali metal to the action of an alkyl halid whose halogen is of lower atomic weight than iodin in the presence of a catalyst.

and

11. The improvement in the art of making 12. The improvement in the art of making -tin sub-group, which comprises subjecting metallo-alkyl compounds of metals of the tin sub-group, which comprises subjecting metallo-alkyl compounds of metals of the the metal in alloy with an alkali metal to tin sub-group, which comprises subjecting the action of an alkyl halicl whose halogen the metal in alloy'with an alkali metal to 10 is of lower atomic weight than iodin while the action of an alkyl halid whose halogen 5 maintaining a temperature above the normal is of lower atomic weight than-iodin.

boilingngoint of the alkyl halid. CHARLES A. KRAUS. 13. e improvement in the art of making CONRAL C. CALLIS. 

